- Common Peroneal Nerve:
- from posterior branches: L4, L5, S1, S2;
- nerve to short head of biceps femoris arises from lateral side of sciatic nerve (common peroneal portion) in middle of thigh & enters
superficial surface of the muscle;

- Sciatic Nerve in THR: - protection of sciatic nerve in THR
-nerve injuries from THR
- in THR the sciatic nerve may be injured by excessive tension when extremity has been lengthened significantly, especially in pts w/ DDH ;
- sciatic nerve is at risk during leg lengthening;
- peroneal division is most often affected;
- w/ sciatic nerve injury following THR, keep pts leg flexed over side of bed;
- if injury was due to traction, the nerve may recover in the relaxed position;